Roles of Epstein–Barr virus viral load monitoring in the prediction of posttransplant lymphoproliferative disorder in pediatric liver transplantation

Abstract

Background/Purpose: This study is aimed to investigate the risk factors and clinical characteristics of posttransplant lymphoproliferative disorder (PTLD) after conducting Epstein–Barr virus (EBV) viral load monitoring in pediatric liver transplant (LT) patients in Taiwan, where EBV infection is endemic. Methods: From 2007 to 2013, pediatric LT recipients who underwent EBV viral load monitoring within 3 months after LT were recruited in this study. The impact of clinical parameters—including age at LT, sex, peak EBV viral load and immunosuppressant levels after LT—on the risk of PTLD were assessed. Results: A total 39 patients underwent LT at a median age of 1.3 years (range: 0.6–14.0 years), and 5 patients developed PTLD during follow-up. Cox's proportional-hazards model identified two predictors of PTLD: peak EBV viral load within 3 months of LT >4100 copies/μg peripheral blood mononuclear cells (PBMC) DNA and peak tacrolimus level within 3 months of LT >14.8 ng/mL (Hazard ratio = 17.14 and 11.54, P = 0.02 and 0.03, respectively). Kaplan–Meier survival analysis revealed significant higher cumulative incidence rates of PTLD (27.3% and 41.8% at 0.3 and 1.2 years after LT) in subjects with peak EBV viral load >4100 copies/μg PBMC DNA within 3 months after LT. (P = 0.001, log-rank test). Conclusion: Close monitoring of EBV viral load within 3 months after LT is helpful to predict a high risk of PTLD. Tapering of immunosuppressants is suggested if the EBV viral load is >4100 copies/μg PBMC DNA in LT children. Keywords: Epstein–Barr virus infections, Liver transplantation, Lymphoproliferative disorders, Pediatrics, Viral load